基于现场和室内剪切试验的原状黄土强度特性研究  

Strength characteristics of undisturbed loess based on field and laboratory shear tests

作　　者：张建华 姚志华[2] 冯世清 黄练红 杨东 赵杰 丁林 ZHANG Jianhua;YAO Zhihua;FENG Shiqing;HUANG Lianhong;YANG Dong;ZHAO Jie;DING Lin(China Southwest Geotechnical Investigation&Design Institute Co.,Ltd.,Chendu 610052,Sichuan,China;Department of Airdrome Construction Engineering,Air Force Engineering University,Xi’an 710038,Shaanxi,China)

机构地区：[1]中国建筑西南勘察设计研究院有限公司,四川成都610052 [2]空军工程大学机场建筑工程系,陕西西安710038

出　　处：《水利水电技术（中英文）》2021年第6期188-197,共10页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(11972374)。

摘　　要：原状黄土的强度参数取值是高陡原状黄土边坡稳定性分析的重要环节,由于目前对于采用何种试验方法取得原状黄土的强度参数尚未有统一的认识,针对试验方法对强度参数取值影响的实际问题,为合理确定高陡原状黄土边坡稳定性分析中强度参数,依托某机场削方形成的高陡原状黄土边坡治理工程,以非饱和原状黄土(Q 3 eol)为研究对象,采用现场剪切试验及室内直剪试验对其强度参数进行测试,着重探究试验方法对强度参数的影响机制。研究结果表明,同一初始物理条件下,现场剪切试验所得原状黄土强度参数较室内试验普遍较低。现场试验与室内试验所得内摩擦角比值约在0.77~0.87之间,而黏聚力比值约在0.84~0.89之间。该差异主要与试验条件、尺寸效应、侧限约束以及有效接触面积等因素密切有关,从而重要和永久性边坡工程的强度参数取值宜采用现场原位剪切试验测试结果。研究成果可为高陡黄土边坡稳定性分析中的强度参数取值以及同类工程建设提供一定借鉴。The value of shear strength parameters is the important key to analyze the stability of high steep undisturbed loess slope.As no unified understanding is there about which test method can be used to obtain the strength parameters of the undisturbed loess at present,the unsaturated undisturbed loess(Q 3 eol)is taken as the study object herein by relying on the treatment project of the high-steep undisturbed loess slope formed by the earthwork cutting for the construction of an airport,so as to reasonably determine the strength parameters in the stability analysis of the high-steep loess slope for the actual problem of the influence from test method on the determination of the strength parameter values;for which in-situ shear test and indoor direct shear test are adopted to test the relevant strength parameters,while the mechanism of the influence from test method on the strength parameters is emphatically explored as well.The study result shows that the strength parameters obtained from the in-situ shear test are generally lower than those got from the indoor test under the same initial physical conditions.The ratios of the internal friction angle and cohesion obtained by both the in-situ test and the indoor test are 0.77~0.87 and 0.84~0.89 respectively,of which the differences are closely related to the test conditions,size effects,lateral restraints,effective contact areas,etc.,thus it is better to determine the values of the strength parameters with the results from the in-situ test for important and permanent slope works.The study result can provide certain references for the determination of the strength parameters in the stability analysis for high-steep loess slope and the construction of the similar project concerned.

关 键 词：非饱和原状黄土 黏聚力 内摩擦角 现场剪切试验 尺寸效应 抗剪强度 力学性能 影响因素 

分 类 号：TV213.4[水利工程—水文学及水资源]